No BackStage Pass for Nested Classes in C#

In java land, I used to use nested classes to simplify a class that was getting complicated. If a class grew a cluster of fields and logic related to a single concept, I would create an inner class to encapsulate all that thus making the outer class simpler to understand--basic OO modularity/cohesion principles. Yes, some folks don't like inner classes and in java the compiler actually opens up the access modifiers of the fields--but I found it useful. But in C#, the nested class doesn't share any special access into the outer/enclosing class (perhaps for security reasons?). The workaround seems to be to pass in an instance of the outer class. The problem with this is that without special access to the internals of the outer class (fields, etc), you have to start modifying the access modifiers of the outer class, or start pushing all the state into the nested class via constructors or methods/properties. But that defeats the purpose--the idea was to keep the API to the outer class the same and keep the change encapsulated between the outer and nested class. The workaround I'm using is to have a special method on the outer class that has all the business logic needed to construct the nested class. Not perfect, but it seems like a decent compromise.